[Secondary facial recontouring with micro-porous titanium implants]. / Corrections secondaires de la face par implants en titane.

Facial recontouring has always been a longstanding objective of esthetic or reconstructive surgery. Most often it uses two types of surgical techniques: autologous and alloplastic. In that regard, different surgical techniques have been proposed to enhance facial recontouring. MATERIALS AND METHODS: Through 5 clinical case reports and a literature review, this article explores the use of allopastic microporous titanium implants in secondary volumetric corrections of the face. RESULTS: There is a current lack of evidence regarding the use of microporous titanium implants in volumetric corrections of the face, most papers reporting their use in post-traumatic or post-surgical cranio-facial defects repair. DISCUSSION: Pros and cons of such implants are discussed in association with the usefulness of this surgical technique in daily surgical practice.

[Neonatal pathologies of the lacrimal system]. / Pathologie néonatale du sac lacrymal.

Neonatal obstruction of the distal part of the lachrymal system can lead to dilatation of the lachrymal sac if associated with a canaliculus problem. Clinical presentation is a blue tumor of the internal canthus. This external expansion of the lachrymal sac communicates with a nasal expansion under the inferior nasal turbinate. Even if this typical presentation is spectacular, spontaneous resolution occurs in 80% of cases. There are two main types of progression: an abscess of the lachrymal sac can occur (20%) or bilateral nasal respiratory obstruction in cases of bilateral obstacle because newborns are obligatory nose breathers (<0.1%).

[Congenital cysts, sinuses and fistula of head and neck]. / Kystes et fistules congénitaux de la face et du cou.

Congenital cervical cysts, sinuses and fistulae are uncommon malformations. Diagnosis and management of congenital cervical cysts, sinuses and fistulae requires a good understanding of their embryological development and topography. Thyroglossal duct cysts are most common, followed by branchial cleft anomalies and dermoid cysts. In this review, we discuss both the classical and current aspects of these malformations.

[Reconstruction of hard palate defects using a facial artery musculomucosal flap]. / Utilisation du lambeau myomuqueux pédiculé par l'artère faciale dans les reconstructions palatines.

The facial artery musculomucosal flap (FAMM) is usually used in reconstruction of defects in oral cavity, most frequent being the mouth floor. This flap has many advantages from its surgical procedure, its great reliability, its mucous tissue origin, its usable surface, its large axis of rotation and the little of after-effects of the donor site. The hard palate defects with bucconasal communication can raise difficulties of reconstruction. We show, by a case report, the many advantages of FAMM flap in these reconstructions.

Relevance of Choukroun's Platelet-Rich Fibrin (PRF) and SMAS flap in primary reconstruction after superficial or subtotal parotidectomy in patients with focal pleiomorphic adenoma: a new technique.

AIM OF THE STUDY: Parotidectomy leaves a retromandibular hollow area in proportion with the amount of gland resected. Many surgeons perform primary reconstruction after superficial or subtotal parotidectomy in patients with exo-facial pleiomorphic focal adenoma. Many techniques have been proposed. We present a new technique of filling of the parotidectomy chamber by a second generation leucocyte and platelet concentrate, Platelet-Rich Fibrin (PRF, Choukroun's method). PATIENTS AND METHODS: 10 patients were included in this preliminary study. Subtotal parotidectomy was performed through classic procedure or lifting procedure. The macroscopic security margin of resection usually allowed performance of a SMAS flap. PRF was prepared following the original Choukroun's method. RESULTS AND DISCUSSION: PRF slow resorption after filling of the exeresis cavity, offers a key aesthetic interest. The fibrin matrix of this biomaterial has many angiogenic and healing properties. Synergetic action of the fibrin and the platelets cytokines within PRF may improve revascularization and postoperative resumption of facial nerve function. The membrane formed by the fibrin dense fibrillary network, as well as the SMAS flap, may help to prevent the Frey's syndrome. CONCLUSION: We propose the use of PRF as a filling, healing and interposition material after parotidectomy for benign parotid tumors. Preliminary results are very encouraging. Longer prospective evaluation of this technique is necessary.

Lower respiratory tract foreign bodies: a retrospective review of morbidity, mortality and first aid management.

OBJECTIVES: The authors describe 28 pediatric cases of foreign body inhalation requiring treatment in intensive care units between 1987 and 1999. The purpose of this study was: (1) to analyze the circumstances, diagnostic difficulties and initial treatment of serious foreign bodies and (2) to compare our series with other literature descriptions and define principles for optimal prevention and initial treatment. METHODS: Twenty-one children presented a penetration syndrome, which was responsible in 13 cases for asphyxia with cardiorespiratory arrest. All these children died, regardless of the initial treatment. Seven children were hospitalized for apparent asthmatic symptoms that did not respond to traditional treatment. RESULTS: The inefficiency of external extraction methods like the Heimlich maneuver and the mean delay between clinical signs and initial treatment lead us to propose a new strategy for the emergency treatment of foreign bodies with asphyxia. CONCLUSIONS: We recommend that emergency teams promote the use of a laryngoscope and Magill forceps. Flexible endoscopy is still recommended as the appropriate diagnostic tool to eliminate doubt in the case of a first severe asthma attack.

[Nasal glial heterotopia: embryological and clinical approaches]. / Hétérotopie gliale nasale: approches clinique et embryologique.

INTRODUCTION: Nasal gliomas or heterotopia are nonhereditary congenital malformations composed of heterotopic neuroglial tissue. They usually present in infancy. Evaluation should include preoperative imaging with CT scan and/or MRI to rule out intracranial extension. There have been several cases reported in which nasal gliomas were misdiagnosed as capillary hemangiomas. The differential diagnosis includes prenasal space developmental impairment, which are nasoethmoidal meningoencephaloceles, nasal dermoid and epidermoid cysts. CASE REPORT: We describe the case of a newborn male infant presenting at birth with a paramedial nasal glioma. An embryological and clinical analysis of nasal gliomas is proposed. DISCUSSION: Nasal glioma is an uncommon congenital lesion presenting as a large panel of midline craniofacial anomalies. The embryological and anatomical origins of nasal gliomas are reviewed. The most known embryological theory was described by Grünwald in 1910 and is called the "prenasal space" theory. This theory is very attractive because of the embryopathogenic continuum proposed among dermoids, gliomas, and encephaloceles. In this article, we discuss major embryological theories on nasal gliomas pathogenesis and propose that while the prenasal space theory can explain the occurrence and the continuum between basal anterior or prenasal encephaloceles and gliomas, it cannot explain the occurrence of craniofacial demoids of the same topography. Better knowledge of embryological mechanisms implicated in the pathogenesis of nasal gliomas can help clinical management of this kind of malformations.

[Idiopathic sudden sensorineural hearing loss: a review]. / Surdités brusques idiopathiques.

Idiopathic Sudden Sensorineural Hearing Loss (ISSHL) remains one of the major unsolved otologic emergencies. It is characterized by the onset of an unilateral sensorineural hearing loss developing within 24 hours, and averaging on pure tone audiogram at least 30 dB HL for three subsequent octave steps, with no marked vestibular symptoms and no identifiable cause. ISSHL is a syndrome covering several heterogeneous entities resulting from different pathogenetic mechanisms. At this time, the audiogram is the unique tool which may help clinicians to identify these entities and provide a classification based on 5 types of hearing loss. Numerous experimental and clinical studies have investigated the mechanisms by which infectious, ischemic, mechanic or immunologic insults may induce cochlear dysfunction. However, extrapolation to humans and rationale therapeutic approaches to ISSHL remain uncertain. SSHL being a diagnosis of exclusion, retrocochlear and neurologic etiologies should be eliminated. No argument allows to consider ISSHL a therapeutic emergency. More precisely, the experimental data presently available on cochlear physiology suggests that a treatment could have some chance to be effective if undertaken within minutes following the onset of ISSHL, a condition never encountered in daily practice. Conversely, it is not justifiable to impute the absence of hearing recovery to a delay in therapy. The various therapeutic strategies currently recommended are highly empirical and should be questionned in terms of cost-effectiveness, the most common being high-dose corticosteroids. New investigation tests are required for improving our approach to ISSHL.

[Clinical and embryological approaches to nasal dermoid sinus cysts]. / Kystes et fistules du dos du nez: de l'embryologie à la clinique.

Nasal dermoid sinus cyst (NDSC) is an uncommon congenital lesion presenting as a large panel of midline craniofacial anomalies. Thirty children with nasal midline masses and/or sinus ostia were surgically treated in the pediatric ENT and cervicofacial surgery department of Trousseau's children's hospital (Paris-France) between 1995 and 2002. All our patients underwent radiological evaluation including CT scan (including axial and coronal planes) and/or MRI (in all three planes) in search of intracranial extension. Thirteen of our patients presented with a midline cyst only, ten had nasal pit only, and seven had combined anomalies. Preoperative radiology and surgery showed an intracranial extension in 3 patients, which exhibited contact of the cyst with the dura. Recurrence being expected if any dermal tissues were left in place, "one-time-excision management" was the rule. CT and MR imaging features were reviewed. The external rhinoplasty procedure resulted in a wide surgical approach, low recurrence and good esthetic results. The embryological and anatomical origins of NDSCs are reviewed. Development of NDSC during embryological development implicates two necessary and sufficient conditions: competence of the ectodermal and mesectodermal cells to form dermoid tissue with epithelial-mesenchymal interactions, and a topographical site of ectodermal inclusion, which fits well with the various clinical presentations of NDSCs. We propose to distinguish NDSCs of anterior topography, located at the anterior skull base level from the basal NDSCs, located at the middle skull base level. We reviewed the various localizations of NDSCs, revisiting a forgotten embryological theory, which unify the various clinical localizations of anterior NDSCs.

Evidence for medial/lateral specification and positional information within the presomitic mesoderm.

In the vertebrate embryo, segmentation is built on repetitive structures, named somites, which are formed progressively from the most rostral part of presomitic mesoderm, every 90 minutes in the avian embryo. The discovery of the cyclic expression of several genes, occurring every 90 minutes in each presomitic cell, has shown that there is a molecular clock linked to somitogenesis. We demonstrate that a dynamic expression pattern of the cycling genes is already evident at the level of the prospective presomitic territory. The analysis of this expression pattern, correlated with a quail/chick fate-map, identifies a 'wave' of expression travelling along the future medial/lateral presomitic axis. Further analysis also reveals the existence of a medial/lateral asynchrony of expression at the level of presomitic mesoderm. This work suggests that the molecular clock is providing cellular positional information not only along the anterior/posterior but also along the medial/lateral presomitic axis. Finally, by using an in vitro culture system, we show that the information for morphological somite formation and molecular segmentation is segregated within the medial/lateral presomitic axis. Medial presomitic cells are able to form somites and express segmentation markers in the absence of lateral presomitic cells. By contrast, and surprisingly, lateral presomitic cells that are deprived of their medial counterparts are not able to organise themselves into somites and lose the expression of genes known to be important for vertebrate segmentation, such as Delta-1, Notch-1, paraxis, hairy1, hairy2 and lunatic fringe.

Alveolar soft-part sarcoma of the cheek.

Alveolar soft-part sarcoma is a rare malignant tumour of uncertain histogenesis, the two main sites of which are the lower extremities in adults and the head and neck in children. We know of only three case reports of intraoral locations without tongue involvement. Here, we describe the first case of an alveolar soft-part sarcoma of the cheek which presented in a patient over 30 years old and had an extremely rapid and eventually fatal evolution. We have also reviewed hypotheses about its aetiology.

Anti-apoptotic role of Sonic hedgehog protein at the early stages of nervous system organogenesis.

In vertebrates the neural tube, like most of the embryonic organs, shows discreet areas of programmed cell death at several stages during development. In the chick embryo, cell death is dramatically increased in the developing nervous system and other tissues when the midline cells, notochord and floor plate, are prevented from forming by excision of the axial-paraxial hinge (APH), i.e. caudal Hensen's node and rostral primitive streak, at the 6-somite stage ( Charrier, J. B., Teillet, M.-A., Lapointe, F. and Le Douarin, N. M. (1999). Development 126, 4771-4783). In this paper we demonstrate that one day after APH excision, when dramatic apoptosis is already present in the neural tube, the latter can be rescued from death by grafting a notochord or a floor plate fragment in its vicinity. The neural tube can also be recovered by transplanting it into a stage-matched chick embryo having one of these structures. In addition, cells engineered to produce Sonic hedgehog protein (SHH) can mimic the effect of the notochord and floor plate cells in in situ grafts and transplantation experiments. SHH can thus counteract a built-in cell death program and thereby contribute to organ morphogenesis, in particular in the central nervous system.

A case of primitive floor of the mouth paraganglioma in a child: an embryological theory unifying viscerocranium appended paragangliomas.

BACKGROUND: Paragangliomas are unusual tumors in the head and neck originating from the paraganglia or glomus cells of neural crest origin. METHODS: We describe the first case of a primitive paraganglioma of the floor of the mouth presenting in childhood. RESULTS: Complete surgical removal was performed after embolization of the left lingual artery. There was no evidence of either persistent or recurrent disease 5 years after surgery. The embryologic and anatomic origins of head and neck paragangliomas are reviewed. CONCLUSIONS: An embryologic theory based on the common neural crest origin and migration pathways of both autonomic viscerocranium appended ganglias and paragangliomas is proposed that unifies the topographically heterogeneous group of viscerocranium-appended paragangliomas.

[Hemifacial microsomia. Embryological and clinical approach]. / Microsomies hémifaciales. Approche embryologique et clinique.

Hemifacial microsomia is an otomandibular dysplasia which includes congenital malformations affecting the jaw and ear apparatus. The knowledge of normal embryonic development is a prerequisite for optimal clinical management of those malformations. The development of craniofacial structures is a multi-step process, which involves many developmental events ranging from the migration of neural crest cells from the neural folds of the young neurula embryo to molecular signaling interactions that coordinate outgrowth and patterning of the facial primordia. Our current knowledge of craniofacial development is limited, but the use of animal developmental models will contribute significantly to our understanding of human otomandibular dysplasias. In this review we discuss both the classical and current aspects of otomandibular development. A clinical approach to hemifacial microsomia is proposed. Current pathogenetic hypotheses of hemifacial microsomia and also mandibulofacial dysostosis are reviewed.

[Regression of Hensen's node and axial growth of the embryo]. / Recul du noeud de Hensen et croissance axiale de l'embryon.

Hensen's node is the gastrulation center in the avian embryo. It is the homologue of the amphibian dorsal blastopore lip and the zebrafish shield. It contains the progeny of all midline cells (floor plate of the neural tube, notochord and dorsal endoderm). However, microsurgical experiments on Hensen's node allow to think that organizer function is due to an extremely limited region situated in the caudal part of Hensen's node which corresponds to the boundary between prospective axial mesoderm rostrally and paraxial mesoderm caudally. This interface is essential for Hensen's node regression and organization of the caudal part of the body.

Defining subregions of Hensen's node essential for caudalward movement, midline development and cell survival.

Hensen's node, also called the chordoneural hinge in the tail bud, is a group of cells that constitutes the organizer of the avian embryo and that expresses the gene HNF-3(&bgr;). During gastrulation and neurulation, it undergoes a rostral-to-caudal movement as the embryo elongates. Labeling of Hensen's node by the quail-chick chimera system has shown that, while moving caudally, Hensen's node leaves in its wake not only the notochord but also the floor plate and a longitudinal strand of dorsal endodermal cells. In this work, we demonstrate that the node can be divided into functionally distinct subregions. Caudalward migration of the node depends on the presence of the most posterior region, which is closely apposed to the anterior portion of the primitive streak as defined by expression of the T-box gene Ch-Tbx6L. We call this region the axial-paraxial hinge because it corresponds to the junction of the presumptive midline axial structures (notochord and floor plate) and the paraxial mesoderm. We propose that the axial-paraxial hinge is the equivalent of the neuroenteric canal of other vertebrates such as Xenopus. Blocking the caudal movement of Hensen's node at the 5- to 6-somite stage by removing the axial-paraxial hinge deprives the embryo of midline structures caudal to the brachial level, but does not prevent formation of the neural tube and mesoderm located posteriorly. However, the whole embryonic region generated posterior to the level of Hensen's node arrest undergoes widespread apoptosis within the next 24 hours. Hensen's node-derived structures (notochord and floor plate) thus appear to produce maintenance factor(s) that ensures the survival and further development of adjacent tissues.